East / West Spring Lake Wastewater Expansion Pilot

Program

Workshop – Water Quality ReviewJuly 1, 2013

Purpose Regulations OSTDS Evaluation – East & West Spring

lake Sampling & Test Results Other Contributors Soils Data Relevant Studies Summary

PRESENTATION OUTLINE

Provide a summary of Water Quality Data collected within the East & West Spring Lake Area

Provide a summary of similar studies Provide a summary of

Regulations Provide a correlation with

Onsite Sewage Treatment and Disposal Systems (OSTDS)

Purpose

62E-06, Florida Administrative Code◦ OSTDS Regulations

62-302, Florida Administrative Code◦ Numeric Nutrient Criteria

Manchester Lock Permit

Regulations

Provides requirements for OSTDS construction & repair

1983 standards changed◦ Separation from seasonal high water table Increased from

12-inches to 24-inches◦ Setback from water body Increased from 50-feet to 75-

feet*◦ Septic tank and drainfield sizes increased

Sizes dependent on structure size

* Charlotte Code of Ordinances (3-7-56) restricts setback to 150-feet for tidally influenced water bodies

62E-6 OSTDS REGULATIONS

1983 standards changed◦ Separation from seasonal high water table Increased

from 12-inches to 24-inches◦ Setback from water body Increased from 50-feet to

75-feet*◦ Septic tank and drainfield sizes increased

Sizes dependent on structure size

* Charlotte Code of Ordinances (3-7-56) restricts setback to 150-feet for tidally influenced water bodies

62E-06 REGULATIONS CONT’D

7

62E-06 REPAIR REQUIREMENTS

WSWT

Septic Tank

Current Drainfield

6" (pre-1983)

Conventional Septic System

8

WSWT

Septic Tank

Drainfield

Pre 1983 homes that fail or have less than 6 inches to WSWT line will have to meet a 12-inch separation

Mound

6"

Tank & Pump

12"

62E-06 REPAIR REQUIREMENTS CONT’D

9

WSWT

Septic Tank

Drainfield

Post 1983 homes that fail or have less than 12 inches to WSWT line will have to meet a 24-inch separation

Mound

12"

Tank & Pump

24"

62E-06 REPAIR REQUIREMENTS CONT’D

Set nutrient loading limitations for estuaries◦ Arithmetic mean shall not to be exceeded more than

once in a 3-year period

62-302 NUMERIC NUTRIENTS

Region Total

Phosphorous

Total Nitrogen Chlorophyll a

4. Charlotte

Harbor Proper

0.19 mg/L 0.67 mg/L 6.1 µg/L

FDEP Permit 08-0210682-001◦ “A Phased Sewer Expansion – include in the

Charlotte County Sewer Expansion Plan those portions of the Alligator Bay Drainage Basin that have been shown to contribute to declining water quality (pre-1983 septic tanks)”

Manchester Lock Permit

1,708 recorded OSTDS’s in East/West Spring Lake

452 vacant lots Buildout percentage = 80% 1,286 OSTDS (75.3%) installed prior to 1983

OSTDS EVALUATIONS

OSTDS EVALUATIONS CONT’D

-

200

400

600

800

1,000

50's 60's 70's 80's 90's 00's

40

260

930

346

92 40

Systems Installed by Decade

No. Systems

-

500

1,000

51 yrs old& older

41-50 yrsold

31-40 yrsold

21-30 yrsold

11-20 yrsold

10 yrs old& newer

54 309

923

312 74 36

System Age

No. Systems

Water level data was collected in East/West Spring Lake to determine water table relative to ground surface

To meet 24-inches of separation for current regulations, the seasonal high water table should not be within 3.5 feet of ground surface or below land surface (BLS)

OSTDS EVALUATIONS CONT’D

Parameter June September November January

Mean Water Level (BLS)* 2.1 ft 2.1 ft 3.1 ft 3.9 ft

Number of samples < 3.5 ft BLS 39 35 29 16

Percentage < 3.5ft BLS 80% 80% 64% 42%

OSTDS EVALUATIONS CONT’D

Groundwater Elevations in East & West Spring Lake

* Based on mean water levels, it is estimated that the majority of the systems do not meet current or past separation requirements and some drainfields may be within the water table a portion of the year.

Ordinance 2007-061: Management of OSTDS Since adoption (2007 to Present), 250

repairs have been made in East & West Spring Lake

Prior to adoption (1950s to 2007), 132 repairs had been made

When a failure occurs, regulations require OSTDS to meet current standards. If separation from seasonal high water table cannot be met, the replacement system must be elevated (mounded)

OSTDS EVALUATIONS CONT’D

More expensive More maintenance / pump failure Affects aesthetics Difficult to maintain grounds Limits use of property Drainage problems Special construction needs:

◦ Dosing chamber◦ Pump◦ Retention/landscape wall

Mound System Impacts

23

Mound System Aerial View

24

50+ wells installed throughout East & West Spring Lake

21 canal sample points within & upstream of East & West Spring Lake

Wells sampled and tested every 2 months◦ Nitrogen◦ Phosphorous◦ Fecal Coliform◦ Water levels

SAMPLING & TEST RESULTS

  Jun/Jul 2012 Sep/Oct 2012 Jan/Feb 2013 Mar/Apr

2013

Low 0.004 mg/L 0.004 mg/L 0.004 mg/L 0.004 mg/L

High 19.439 mg/L 4.692 mg/L 17.33 mg/L 39.17 mg/L

Water Table 2.1 ft BLS 2.1 ft BLS 3.1 ft BLS 3.9 ft BLS

Average .605 mg/L 0.184 mg/L 0.743 mg/L 1.02 mg/L

NITROGEN RESULTSNitrogen Concentrations in East & West Spring Lake

  Jun/Jul 2012 Sep/Oct 2012 Jan/Feb 2013 Mar/Apr 2013

Low .004 mg/L 0.004 mg/L 0.004 mg/L 0.004 mg/L

High 0.033 mg/L 0.062 mg/L 0.033 mg/L 0.038 mg/L

Average 0.021 mg/L 0.03 mg/L 0.013 mg/L 0.012 mg/L

Nitrogen Concentrations in Canal System

  Jun/Jul 2012 Sep/Oct 2012 Jan/Feb 2013 Mar/Apr 2013

Low .02 mg/L 0.02 mg/L 0.11 mg/L 0.15 mg/L

High 4.05 mg/L 13.53 mg/L 5.62 mg/L 31.69 mg/L

Water Table 2.1 ft BLS 2.1 ft BLS 3.1 ft BLS 3.9 ft BLS

Average 1.05 mg/L 1.36 mg/L 1.12 mg/L 2.39 mg/L

PHOSPHOROUS RESULTSPhosphorous Concentrations in East & West Spring Lake

Phosphorous Concentrations in Canal System  Jun/Jul 2012 Sep/Oct 2012 Jan/Feb 2013 Mar/Apr 2013

Low 0.22 mg/L 0.29 mg/L 0.02 mg/L 0.04 mg/L

High 0.66 mg/L 0.52 mg/L 0.32 mg/L 0.42 mg/L

Average 0.42 mg/L 0.41 mg/L 0.18 mg/L 0.23 mg/L

  Jun/Jul 2012 Sep/Oct 2012 Jan/Feb 2013 Mar/Apr 2013

Low 10 col/100 ml 10 col/100 ml 10 col/100 ml 10 col/100 ml

High 2940 col/100 ml 1720 col/100 ml 10 col/100 ml 10 col/100 ml

Water Table 2.1 ft BLS 2.1 ft BLS 3.1 ft BLS 3.9 ft BLS

Average 123.5 col/100 ml 44.9 col/100 ml 10 col/100 ml 10 col/100 ml

FECAL COLIFORM RESULTSFecal Coliform Concentrations in East & West Spring Lake

Fecal Coliform Concentrations in Canal System  Jun/Jul 2012 Sep/Oct 2012 Jan/Feb 2013 Mar/Apr 2013

Low 10 col/100 ml 10 col/100 ml 10 col/100 ml 10 col/100 ml

High 90 col/100 ml 80 col/100 ml 200 col/100 ml 70 col/100 ml

Average 41.3 col/100 ml 29.1 col/100 ml 31.9 col/100 ml 18.1 col/100 ml

Nitrogen◦ Range: 0.004 mg/L to 39.17 mg/L◦ Drinking water limit: 10 mg/L◦ NNC limit: 0.67 mg/L◦ Wells closest to OSTDS had highest recordings◦ Groundwater levels > canal levels◦ Levels highest winter season when winter residents

are present

SUMMARY OF RESULTS

Phosphorous◦ Range: 0.02 mg/L to 31.69 mg/L◦ NNC limit: 0.19 mg/L◦ In wells, 150 of 171 samples tested higher than the NNC limit

(88%)◦ In canals, 55 of 69 samples tested higher than NNC limit

(80%)◦ The average for all samples was 0.895 mg/L, 5 x the NNC

limit◦ Wells closest to OSTDS had highest average recordings◦ Groundwater levels > canal levels◦ Levels highest in winter season when winter residents are

present

SUMMARY OF RESULTS CONT’D

Fecal Coliform◦ Range: 10 col/100 ml to 2940 col/100 ml◦ Multiple samples tested above 400 col/100, two (2)

from the same well◦ Canal levels > groundwater Levels◦ Levels highest during wet Season when soils are

saturated & filtration & adsorption is reduced due to high water table

SUMMARY OF RESULTS CONT’D

Atmospheric◦ Deposition of nutrients from atmosphere

Fertilizer◦ Can result in application of nitrogen & phosphorous◦ Restricted use (Ordinance 2011-017)

No phosphorous application June 1 to September 30 < 4 lbs of nitrogen can be applied / yr / 1,000 sf < 0.5 lbs of phosphorous can be applied / yr / 1,000 sf

Other (Animals, etc.)

OTHER CONTRIBUTORS

Difference between OSTDS and other contributors◦ Nutrients from other contributors are applied in the

atmosphere and are largely taken in by plant life◦ Nutrients from OSTDS are released below the

ground and depend on soils for removal prior to entering groundwater

OTHER CONTRIBUTORS CONT’D

Matlacha Sands Kesson Fine Sand Pineda Fine Sand Oldsmar Fine Sand Common traits of soils in E/W Spring Lake

◦ Gravelly fine sand◦ Poorly drained◦ Unsuitable for drainfields◦ Seasonal high water table within 10-inches BLS◦ Kesson, noted as being located in tidal swamps subject to

tidal flooding

SOIL CLASSIFICATIONS

Charlotte Harbor & Estero Bay Aquatic Preserves Water Quality Status & Trends for 1998-2005◦ Study reviewed water quality data within regions of

Charlotte Harbor & Estero Bay◦ Upper Charlotte Harbor results

Highest phosphorous levels of region Highest single nitrogen recording 70th Percentile of Florida estuaries for Phosphorous 80th Percentile of Florida estuaries for Nitrogen 80th Percentile of Florida estuaries for Fecal Coliform

RELEVANT STUDIES

Effects of Seasonal Variability on Microbial Fecal Pollution and Enteric Pathogens in a Subtropical Estuary◦ 12 sample stations were set within Charlotte Harbor and

sampled monthly for indicator bacteria◦ 4 of the stations were located in the vicinity of East & West

Spring Lake (East Spring Lake, West Spring Lake, Sunrise Waterway & Countryman Waterway)

◦ Of the samples tested, East & West Spring Lakes recorded the highest & 2nd highest fecal levels

◦ Concentrations were highest during wet season

RELEVANT STUDIES CONT’D

Groundwater System Water Quality Data Port Charlotte Area◦ Study performed for the purpose of characterizing surface &

groundwater quality in Port Charlotte◦ 8 study sites selected within a 400 home area◦ Monitoring wells installed to determine direction of

groundwater flow and plume potential for nutrients from OSTDS to edge of lot lines

◦ Average nitrogen levels of 21.62 mg/L at drainfield and 7.92mg/L at lot line

◦ Average phosphorous levels of 26.43 mg/L at drainfield and 14.80 at Lot Line

RELEVANT STUDIES CONT’D

Several factors reviewed link OSTDS’s to decreased water quality in East/West Spring Lake:◦ Soils unsuitable for OSTDS installation◦ A seasonal high water table unsupportive of treatment◦ A population density unfavorable for OSTDS◦ Close proximity to canals◦ Limited treatment capability of OSTDS◦ Test results indicating positive correlation with nutrients &

bacteria◦ Studies indicating high nutrient & fecal levels in upper

Charlotte Harbor, amongst the highest in the State

SUMMARY & CONCLUSIONS

Based on findings and factors and given the age, number of past repairs and projection of future replacement, it is recommended that Charlotte County consider installation of a centralized sewer system

A Centralized Sewer System would:◦ Eliminate dependence on OSTDS◦ Eliminate future OSTDS failure and pollution◦ Be a positive step towards cleaning the groundwater &

surface water and in helping diminish the impairment of Charlotte Harbor

SUMMARY & CONCLUSION CONT’D